preñar
impregnate
pregnant
carrying a developing fetus
+
-ar
verb suffix
Preñar means to impregnate and can be remembered by thinking of the English word pregnant0 + -ar1 (verb1).
verb
  1. impregnate
    To make pregnant, to impregnate
    El toro logró preñar a varias vacas del rebaño. // The bull managed to impregnate several cows in the herd.